reSOLUTION_Research_09_Neuroscience - Leica Microsystems

Widefield microscoPy
The New Understanding of Olfactory Neurosensorics
sniffing out the secrets of
social Behavior
anja schué, leica microsystems
in his novel “Perfume – the story of a murderer”, Patrick süskind put the power of odors into words better than anyone before him.
it may be a fascinating idea, but no one will ever be able to create the perfect fragrance that makes a person irresistibly attractive.
in the animal world, on the other hand, olfactory signals are an essential element of social communication. yet we are only just
beginning to understand the complexities and functional differences of the sense of smell in mammals. Prof. marc spehr, head of
the department of chemosensation at rWtH aachen university since 2009, is researching the neuronal mechanisms of olfactory
perception and signal processing using the mouse model. He and his team are trying to find out how substances for social interaction
are perceived and how this perception generates a specific type of behavior.
fig. 1: Prof. marc spehr tested the new leica dm6000 fs fixed-stage microscope before the market launch.
“We are highly satisfied with the microscope’s optics and stability. We find the large working distance and the
space around the specimen impressive, too. the accessibility to the specimen area is important to neurophysiologists,
as we need a lot of peripheral equipment.”
26 resolutioN
Prof. spehr, why are scientists becoming
more and more interested in the nose?
you could say this was triggered by the discovery
of the multigene family of olfactory receptors by
linda b. buck und richard axel in 1991, for which
both were awarded the nobel Prize in 2004. since
then, the nose, in particular the subject of molecular
chemosensation, is definitely ”en vogue”. We have
only recently gained new and exciting information
that puts some of our previous knowledge of the
mammalian sense of smell in jeopardy. We used to
think the olfactory system consists of only two anatomically
and functionally separate components:
the nasal membrane or main olfactory system that
actually smells, and the vomeronasal organ (Vno)
or accessory olfactory system that detects socially
relevant chemosignals, often referred to as pheromones.
today, two additional olfactory subsystems, the
septal organ and the grüneberg ganglion, have been
discovered or rediscovered. and not only that – we
now know that the functional structure of the sense
of smell is far more complex and differentiated. for
instance, some social signals are recognized via the
main olfactory epithelium, just as some ‘conventional’
odors are detected via the Vno. Within the subsystems,
different neuron families are specialized
for specific sensory stimuli and exhibit characteristic
axonal projection patterns. in the last five years
in particular, groundbreaking discoveries about
such specialized nerve cells in the main olfactory